I believe you may be surprised with your front blade.
I have been changing out my Handi/44 rear sight with others seeking an option to the factory rear also.
I mounted a Springfield 73 TD sight to the rear on my rifle. I was concerned as you are with the front. The height was fine.
My Selection is a 1898 30-40 Krag sight that will be mounted in the mid-barrel location. I need to have a Gunsmith drilled and tapped one hole for the permanent install. For the testing I mounted it by the front mount hole of the sight and attached to the factory rear drilled and tapped mid-barrel location.
I did not like the rear location of an Iron sight. The sight is blocked by the hammer, till the hammer is in cocked. For me this is a distraction, as my rifle is a multi-purpose firearm. For target shooting the location would be fine. For other functions, not so good.
I want to say ,who ever drilled and tapped my barrel at the factory for the Iron sights and the scope rail. Thank you for an excellent job of precision measurement. The sights when mounted require no windage adjustment necessary. The Krag sight has no windage and is in perfect alignment with the front sight.
Try your new rear with the existing front. You can change it out if need be later if you need a different one.